add docker

Cargo.toml

@@ -1,9 +1,11 @@
 [package]
 name = "random"
 version = "0.1.0"
-edition = "2021"
+edition = "2018"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[[bin]]
+name = "random"
+path = "src/main.rs"
 
 [dependencies]
 hyper = { version = "^0.14", features = ["full"] }